Pre-cooling system for an air conditioning condenser

ABSTRACT

A pre-cooling system for use with a condenser of an air conditioning system is provided. In one embodiment, the pre-cooling system comprises a housing that is coupleable to a top of a condenser of an air conditioner wherein the condenser has a substantially-vertical exhaust. The pre-cooling system further comprises a valve mounted in the housing that is coupleable to a water source and wherein the valve is capable of operating independent of electrical power. The pre-cooling system further comprises a vane that is coupled to the valve and positionable in the substantially-vertical exhaust, wherein the vane has an aerodynamically-shaped cross section useable to operate the valve. The present invention further provides a method of manufacturing the pre-cooling system.

TECHNICAL FIELD OF THE INVENTION

The present invention is directed, in general, to air conditioningsystems and, more specifically, to a pre-cooling system for an externalair conditioner condenser.

BACKGROUND OF THE INVENTION

Air conditioner condenser units have evolved since early units thatgenerally were horizontal air flow, i.e., air discharge is substantiallyparallel to the ground or unit base, to the more modern condensers withside air inlet and vertical air discharge. Meanwhile, the concept ofspraying a mist of cool water on or around external condenser units ofair conditioners in order to improve their efficiency has been. Severalpatents have been issued disclosing various details of and improvementsto this technology, some of which are limited by the assumption of ahorizontal flow condenser or a vertical flow condenser as will bedetailed below.

One early system discloses a water reservoir that resides below thecondenser coils with the water drawn from the reservoir and pumpedupward to be sprayed onto the condenser and then running down into thereservoir. Thus, a pool of water is constantly in evidence below thecondenser, and is a prime breeding ground for mosquitoes and algae.Other systems disclose the use of a compressor relay that iselectrically connected to a compressor and a water valve. The compressorrelay is activated by electrical power to the compressor. The use of anelectrical switch to operate an electrical valve adds needless cost andcomplexity to the system. Additionally, this system requires at least aminimal knowledge of electricity for the installer because thecompressor electrical circuit must be tapped in order to activate thewater valve. Installation of the device by a property owner would beimpractical for most non-skilled persons due to a general respect for orfear of electricity.

Other systems have employed a paddle switch or paddle valve that isactivated by airflow created when the fan for the condenser is running.However, certain problems have been found with these units. One devicedescribes a horizontal air flow condenser with an airflow-operatedpaddle valve assembly conventionally fixed to the air conditionerhousing in the path of the horizontally-exhausted air stream. In thiscase, the paddle pivots on a horizontal pin under the force ofhorizontal air from the unit fan, thereby overcoming a spring pressureexerted on the paddle to keep the valve normally-closed. No details ofthe paddle is made, so it is likely that the shape is common, such as:rectangular, circular, or perhaps paddle-shaped, e.g., as in a ping pongpaddle. Another device describes a substantially-circular flat plate,that is designed to be lifted by a vertical current of air when thecondenser fan is operating. The description does not make it clearwhat-minimum force must be exerted by the vertical exhaust to move theflat plate and operate the valve. Attempts by the present inventor touse a substantially-circular paddle with current vertical dischargecondenser units was met with substantial failure. The plain paddle couldnot be made to operate a suitable valve.

Another device describes a pneumatically operated paddle that operates apinch valve inexpensively constructed of polyvinylchloride, morecommonly know as PVC, and flexible tubing. It would appear obvious toone of skill in the art that repeated pinching of the tube as the systemoperates will seriously shorten the life of the tubing.

Another system requires a temperature sensor for activating the watermist when the temperature in the condenser reaches a predeterminedpoint. This is an unnecessary complication of the system. Other systemsemploy one or more of: a vibration transducer, battery backup power,temperature sensing bellows, etc., and unnecessarily complicate thesystem.

Accordingly, what is needed in the art is a condenser pre-cooling systemthat provides the advantages of previous systems but that does notsuffer from the deficiencies of the prior art.

SUMMARY OF THE INVENTION

To address the above-discussed deficiencies of the prior art, thepresent invention provides a pre-cooling system for use with a condenserof an air conditioning system. In one embodiment, the pre-cooling systemcomprises a housing that is coupleable to a top of a condenser of an airconditioner wherein the condenser has a substantially-vertical exhaust.The pre-cooling system further comprises a valve mounted in the housingthat is coupleable to a water source and wherein the valve is capable ofoperating independent of electrical power. The pre-cooling systemfurther comprises a vane that is coupled to the valve and positionablein the substantially-vertical exhaust, wherein the vane has anaerodynamically-shaped cross section useable to operate the valve. Thepresent invention further provides a method of manufacturing thepre-cooling system.

The foregoing has outlined preferred and alternative features of thepresent invention so that those skilled in the art may better understandthe detailed description of the invention that follows. Additionalfeatures of the invention will be described hereinafter that form thesubject of the claims of the invention. Those skilled in the art shouldappreciate that they can readily use the disclosed conception andspecific embodiment as a basis for designing or modifying otherstructures for carrying out the same purposes of the present invention.Those skilled in the art should also realize that such equivalentconstructions do not depart from the spirit and scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present invention, reference isnow made to the following descriptions taken in conjunction with theaccompanying drawings, in which:

FIG. 1A illustrates a partial sectional, elevation view of oneembodiment of a pre-cooling system constructed according to theprinciples of the present invention for use with a vertical exhaust airconditioning condenser system;

FIG. 1B illustrates a schematic view of one embodiment of a pre-coolingsystem constructed according to the principles of the present invention

FIG. 2 illustrates a partial sectional view of the valve and the vane ofFIG. 1 along plane 2-2 when the fan is not operating;

FIG. 3 illustrates a cross sectional view of a portion of the vane ofFIG. 1 along the plane 3-3;

FIG. 4 illustrates a sectional view of the valve and the vane of FIG. 1along plane 2-2 when the fan is operating; and

FIG. 5 illustrates a plan view of a pre-cooling system kit for use inretrofitting an existing air conditioning condenser and constructedaccording to the principles of the present invention.

DETAILED DESCRIPTION

Referring initially to FIG. 1A, illustrated is a partial sectional,elevation view of one embodiment of a pre-cooling system 100 constructedaccording to the principles of the present invention for use with avertical exhaust air conditioning condenser system 190. The verticalexhaust air conditioning system 190 shown is typical of condenser units191 currently used for residential and commercial applications. Thecondenser unit 191 typically has two or three open (unblocked) sides 192a-192 b, (192 c not visible), an open top 193 and a condenser coil 194.A fourth side 192 d has mechanical and electrical connections to anevaporator 195 and thermostat 196 located within a cooled environment197 served by the air conditioner 190. Ambient air 199 to cool thecondenser coil 194 is drawn in through the open sides 192 a-192 c of thecondenser unit 191 and exhausted through the top 193 by an electric fan198 having a plurality of fan blades 198 a. A force generated by theelectric fan 198 is limited by the power of an electric motor 198 b andthe design of the fan blades 198 a which are generally designed only tomove a desired amount of air per unit time through the condenser coil194. The air 199 passes through the condenser coil 194 and is ejected asexhaust 189 in a substantially-vertical direction. In some condenserapplications, the condenser unit 191 may employ fixed grillwork 193 a orfixed baffles (not shown) in the exhaust 189 to direct the exhaust in amore structured way and to prevent personnel injury from the rotatingfan blades 198 a.

Referring now to FIG. 1B with continuing reference to FIG. 1A,illustrated is a schematic view of one embodiment of a pre-coolingsystem 100 constructed according to the principles of the presentinvention. The pre-cooling system 100 comprises: a housing 110, a valve120, a vane 130, a water supply tube 140, a spray nozzle 150, spraytubing 160, a filter 170, and a hose coupling 180. In a preferredembodiment, the filter 170 comprises an in-line water filter having anominal 5-micron polyethylene element designed to remove non-dissolvedimpurities, and additionally hexametaphosphate to treat the water.

Hexametaphosphate is a slow-dissolving, crystalline, food-gradephosphate especially formulated to-control corrosion, lime/scaleaccumulation and iron oxide precipitation in commercial andinstitutional service water systems. The chemicals used to manufacturehexametaphosphate are listed in the Federal Register No. 227, Nov. 20,1959, page 9369. Most water supplies produce corrosion, scale, or “redwater” problems. Although soft ground water supplies may ensure freedomfrom scale, they generally present serious corrosion problems. However,with subsurface hard bicarbonate waters corrosion is usuallyovershadowed by the accumulation of efficiency-robbing lime scaledeposits. Freedom from serious corrosion and scaling problems does notguarantee freedom from discolored water, staining or fouling of linesand equipment if the water contains dissolved iron. When used in a watersystem, hexametaphosphate forms a thin protective phosphate film on allmetal surfaces contacted, thereby reducing corrosive action of thewater. The film does not build upon itself and cannot interfere withheat transfer. This protective film must be maintained to providecontinuous protection. Hexametaphosphate does not remove or reducehardness in the water, but simply prevents precipitation of the hardnesson the surfaces of the equipment. Of course, other suitable filteringmaterials may also be used.

In one embodiment, the filter 170 is equipped with a ¾″ female fitting171 on the inlet side and a ¾″ male fitting 172 on the outlet side. Thefemale fitting 171 is configured to couple to a water source 173 and themale fitting 172 couples to a female hose coupling 141 of the watersupply tube 140.

In a preferred embodiment, the housing 110 is formed of a rigid plasticand coupled to the top 193 of the condenser unit 191 with double-sidedtape (not shown). Alternatively, the housing 110 may be coupled to thetop 193 by any other suitable means, e.g., zip ties, cable ties, safetywire, etc. In the illustrated embodiment, the housing 110 is coupled tothe top 193 at a center panel 193 b, enabling the vane 130 to bepositioned over the grillwork 193 a where the exhaust air 189 will exitthe condenser unit 191.

Referring now to FIG. 2 with continuing reference to FIGS. 1A and 1B,illustrated is a partial sectional view of the valve 120 and the vane130 of FIG. 1 along plane 2-2 when the fan 198 is not operating. Thevalve 120 is mounted within the housing 110 and is coupled in fluidcommunication with the water supply tube 140. The valve 120 is furthercoupled to and in fluid communication with the spray tubing 160 and thespray nozzle 150. In the illustrated embodiment, the spray tubing 160 isa plurality of sections of spray tubing 160 coupled to and in fluidcommunication with a like plurality of spray nozzles 150. Of course, thenumber of spray nozzles 150 may be tailored to the size and orientationof the sides 192 a-192 c of the condenser unit 191. In a preferredembodiment, the valve 120 is a pin valve 120 having a pin 221 and a seat222. When the fan 198 is not operating, the vane 130 rests in a downposition, not quite on the grillwork 193 a, due to gravity. The vane 130is capable of pivoting at least some amount about axis 231. When thevane 130 is pivoted to the position shown, surface 232 of the vane 130bears upon and mechanically forces the pin 221 against the seat 222 sothat the valve 120 is closed. A rubber O-ring may be located about anend of the pin 221 to seal against the seat 222. With the valve 120closed when the vane 130 is near, but not on the grillwork 193 a, wateris prevented from flowing from the water source 173 to the spray tubing160 and to the spray nozzles 150. Because the valve 120 is mechanicallyclosed, the valve 120 operates independently of any electrical source.

Referring now to FIG. 3 with continuing reference to FIGS. 1A, 1B, and2, illustrated is a cross sectional view of a portion of the vane 130 ofFIG. 1 along the plane 3-3. The vane 130 has an aerodynamically-shapedcross section 331 having a leading edge 332 and a trailing edge 333. Thevane 130 further has a leading edge thickness 334 and a trailing edgethickness 335. As can be seen, the leading edge thickness 334 issubstantially thicker than the trailing edge thickness 335. One who isof skill in the art will recognize that the vane 130 has a first point341 on the leading edge 332 that is furthest from the trailing edge 333.Likewise, the vane 130 has a second point 342 on the trailing edge 333that is furthest from the leading edge 332. A straight line 336 drawnbetween the first point 241 and the second point 342 describes a chord336 of the cross section. Further, the vane 130 has a concaveundersurface 337 and an uppersurface 338.

One who is of skill in the art will recognize that the vane 130 isaerodynamically sculpted (e.g., an airfoil) in that the uppersurface 338is longer than the undersurface 337. In a highly simplified form (a2-dimensional model for a 3-dimensional problem) for subsonic airflow(such as the vane 130 will experience due to the exhaust 189), themolecules of air passing the leading edge point 341 divide into thosemolecules flowing over the uppersurface 338 and those molecules flowingalong the undersurface 337. The molecules thus divided must rejoin inthe free stream air 188 above the vane 130. That is the air thatinitially strikes the first point 341 divides into a first air flow 343over the uppersurface 338 and a second air flow 344 under theundersurface 337. As the distance is longer over the uppersurface 338,the air molecules must travel faster in that area than along theundersurface 337. This difference in air molecule velocity creates adifference in air pressure exerted on the undersurface 337 and theuppersurface 338. This effect is described by Bernoulli's Principle,i.e., a lower pressure is evident where fluid motion is faster across asurface. Thus, there is a lower pressure on the uppersurface 338 than onthe undersurface 337, giving a net difference in pressure that is thelift L generated by the aerodynamics of the vane 130. With anaerodynamically-shaped cross section 331 formed in the vane 130, thelifting force L created was sufficient to raise the vane 130, andrelieve pressure from surface 232 on the pin valve 120 allowing water toflow through the valve 120 to the spray tubing 160 and the spray nozzles150.

Referring now to FIG. 4, illustrated is a sectional view of the valve120 and the vane 130 of FIG. 1 along plane 2-2 when the fan 198 isoperating. When the fan 198 is operating, the vane 130 lifts above thegrillwork 193 a due to aerodynamic lifting as described above. The vane130 pivots about axis 231 relieving pressure from surface 232 on the pin221. When the vane 130 is pivoted to the position shown, water pressurein supply tubing 140 acts upon the pin valve and forces the pin 221 awayfrom the seat 222 so that the valve 120 is open. With water pressure onthe pin 221 from the supply tubing 140, water flows into a chamber 410.Chamber 410 is in fluid communication with the spray tubing 160 and thespray heads 150. Therefore, water is allowed to flow from the watersource 173 to the spray tubing 160 and to the spray nozzles 150. Thus,relieving pressure on the pin 221 allows water pressure to open thevalve 120 and is therefore independent of electrical power of any kind.

Referring now to FIG. 5, illustrated is a plan view of a pre-coolingsystem kit 500 for use in retrofitting an existing air conditioningcondenser and constructed according to the principles of the presentinvention. In one embodiment, the pre-cooling system kit 500 comprises:a housing 510 coupleable to a top of a condenser of an air conditioner,a valve 520 mounted in the housing 510, a vane 530 coupled to the valve520 and having an aerodynamically-shaped cross section, supply tubing540 coupleable to the valve 520 and coupleable to a water source, spraynozzles 550, spray tubing 560, a filter 570, and a hose coupling 580. Ina preferred embodiment, the pre-cooling system kit 500 is installable onan existing vertical exhaust condenser unit of an air conditioningsystem. The pre-cooling system kit 500 may further comprise double sidedtape and zip ties for installation on the condenser.

Thus, a pre-cooling system, pre-cooling retrofit kit, and a method ofmanufacturing the same have been described. The pre-cooling systememploys an aerodynamically shaped vane that operates to close a watercontrol valve without resorting to electrical connections. Waterpressure opens the water control valve when pressure on the pin isrelieved. Therefore, the kit is installable by most homeowners withoutresorting to hiring an electrician. The system has universal applicationto vertical exhaust condensers for both residential and commercial airconditioning systems.

Although the present invention has been described in detail, thoseskilled in the art should understand that they can make various changes,substitutions and alterations herein without departing from the spiritand scope of the invention in its broadest form.

1. For use with a condenser unit of an air conditioner, a pre-coolingsystem, comprising: a housing coupleable to a top of a condenser of anair conditioner, said condenser having a substantially-vertical exhaust;a valve mounted in said housing and coupleable to a water source, saidvalve capable of operating independently of electrically power; and avane having an uppersurface and an undersurface, the vane being coupledto said valve and positionable in said substantially-vertical exhaust,said vane having an aerodynamically-shaped cross section useable tooperate said valve, wherein said uppersurface is of a length longer thansaid undersurface.
 2. The pre-cooling system as recited in claim 1wherein said aerodynamically-shaped cross section has a leading edge anda trailing edge, and wherein said leading edge is substantially thickerthan said trailing edge.
 3. (canceled)
 4. The pre-cooling system asrecited in claim 1 wherein said vane has a concave undersurface.
 5. Thepre-cooling system as recited in claim 1 further comprising a watersupply tube coupled to said valve and coupleable to said water source.6. The pre-cooling system as recited in claim 1 further comprising aspray nozzle in fluid communication with said valve.
 7. The pre-coolingsystem as recited in claim 1 further comprising spray tubing interposedsaid valve and said spray nozzle.
 8. The pre-cooling system as recitedin claim 1 further comprising a filter coupled to said valve andcoupleable to said water source.
 9. The pre-cooling system as recited inclaim 8 wherein said filter comprises hexametaphosphate.
 10. A method ofmanufacturing a pre-cooling system for use with a condenser unit of anair conditioner, said method comprising: providing a housing coupleableto a top of a condenser of an air conditioner, said condenser having asubstantially-vertical exhaust; mounting a valve in said housing, saidvalve coupleable to a water source and capable of operatingindependently of electrical power; and coupling a vane to said valve,said vane having an uppersurface and an undersurface, said uppersurfacebeing of a length longer than said undersurface to form anaerodynamically-shaped cross section and positionable in saidsubstantially-vertical exhaust, said aerodynamically-shaped crosssection useable to operate said valve.
 11. The method as recited inclaim 10 wherein coupling a vane includes coupling a vane wherein saidaerodynamically-shaped cross section has a leading edge and a trailingedge, and wherein said leading edge is substantially thicker than saidtrailing edge.
 12. The method as recited in claim 11 wherein coupling avane includes coupling a vane wherein a straight line drawn between saidleading edge and said trailing edge defines a chord of saidaerodynamically-shaped cross section, and wherein said chord and adirection of said substantially-vertical exhaust define an angle ofattack of said vane.
 13. The method as recited in claim 10 whereincoupling a vane includes coupling a vane having a concave undersurface.14. The method as recited in claim 10 further comprising coupling awater supply tube to said valve, said water supply tube coupleable tosaid water source.
 15. The method as recited in claim 10 furthercomprising coupling a spray nozzle in fluid communication with saidvalve.
 16. The method as recited in claim 10 further comprisinginterposing spray tubing between said valve and said spray nozzle. 17.The method as recited in claim 10 further comprising coupling a filterto said valve, said filer filter coupleable to said water source. 18.The method as recited in claim 17 wherein interposing a filter includesinterposing a filter comprising hexametaphosphate.